Roads, including both highways and racetracks, are often bounded along their edges by rigid barrier walls. Such barrier walls protect both structures and people adjacent the road by preventing vehicles from accidentally leaving the road or adjacent shoulders. However, such rigid barriers or barrier walls, alone, do not effectively absorb energy during collision with a vehicle. As a result, collisions of the vehicle and the barrier wall often result in great damage to the vehicle and personal injury to the vehicle's driver and passengers. To further protect the vehicle and its driver and passengers many barrier walls now include energy absorbing systems which typically include compressible materials adjacent to the perimeter of the road. Such compressible materials do not effectively attenuate the G-forces created during a crash or collision with a vehicle. In many situations, other vehicles following the first crash will lose control attempting to avoid the first accident which results in second-vehicle crashes. However, due to damage to the compressible materials from the first vehicle crash, these compressible materials are ineffective against further impacts or vehicles crashes. In addition, reconstruction and replacement of the compressible materials is time consuming and expensive.
Compressible over-lapping fender-like devices have been disclosed which will absorb the energy of impact during a collision. These devices are L-, T-, or Z-shaped fenders which become compressed during collision. However, once compressed, these devices remain compressed and must be replaced.